M varies directly with the square of D and inversely with the square root of x; m=20 when d=5 and x=4

Question

 

​(Use integers or fractions for any numbers in the​ expression.)

Answer 1

m=kd^2/sqrx

20=25k/2

25k = 40

k = 40/25=8/5

m= 8d^2/5sqr(x)